As I said in the video description, you should also be able to verify this information in the video and what is written below by finding the correct wire diagram in the manual that comes with the soft start kit and comparing the diagram and model number to the diagram on the inside cover of the wiring box for your AC or Heat Pump. For the Heat Pump version there are two black wires that are crimp nut connected on the heat pump. The soft start has a black wire with a light blue connector on the end. Cut off the crimp nut and the light blue connector and wire nut all three together. (@7:21). Those are the only black wires available. In the AC only version there is a black wire and a purple wire that are wired together on the AC unit. The soft start has a black wire with the light blue connector. Cut the ends off and wire nut those together. (@10:05)